A clinical research project is investigating the hyperglycemia of CF by determining the levels and interrelations of hormones regulating blood glucose in patients as they progress from normal glucose tolerance to severe intolerance and by evaluating the pathophysiologic effects of the hyperglycemia. Ten CF patients with hyperglycemia and twenty CF patients without hyperglycemia have been studied using a series of tolerance tests. Only four of the nonhyperglycemic patients had normal carbohydrate tolerance, while sixteen revealed a delayed and excessive response to oral and intravenous glucose. Two research projects are investigating epithelia water the electrolyte transport with the long term objective of understanding the pathophysiology of the exocrine electrolyte abnormalities of CF. One of these projects is using the rat parotid retrograde perfusion assay as a guide in the purification and characterizaton of the sodium transport inhibitors present in CF secretions. These studies have found that polyamine-derived polycations isolated from CF seminal plasma inhibit sodium transport and that the inhibitors present in CF saliva have properties similar to the polyamine-derived polycations. A second project is investigating cellular mechanisms of epithelia in which electrolyte transport is sensitive to secretions or serum of CF patients. These studies have led to the development of a method to measure anion translocation across isolated intestinal brush border membranes. Saliva from control or CF patients fails to effect sodium or glucose transport in small intestinal brush border membranes. However, serum from either group of subjects does decrease glucose transport in these membranes. BIBLIOGRAPHIC REFERENCES: Boxerbaum, B., Doershuk, C.F., Stern, R.C., Boat, T.F., Primiano, F.P. Jr., and Matthews, L.W.: Cystic Fibrosis: an Obstructive Pulmonary Disease of Children and Adults. A Booklet, 1975. Stern, R.C., Stevens, D.P., Boat, T.F., Doershuk, C.F., Izant, R.J. and Matthews, L.W. Symptomatic Hepatic Disease in Cystic Fibrosis: Incidence, Course and Outcome of Portal Systemic Shunting. Gastroenterology 70 (5):645, 1976.